New Zealand has updated travel advice for the Middle East, warning the military conflict between Iran and the United States could escalate further in coming days.

The Iran war began when the United States and Israel attacked Iran on February 28 this year and Iran responded with its own strikes on Israel and Gulf states that host ⁠US bases.

US-Israeli strikes on Iran and Israeli attacks on Lebanon during the war have killed thousands of people and displaced millions.

In New Zealand, the Ministry of Foreign Affairs' Safe Travel site said the situation remained unpredictable, with military strikes and reprisal attacks happening in a number of locations.

If the security situation deteriorated further, there could be travel disruption and airspace closures.

The alert warned that Kiwis travelling through Middle East transit hubs could become stranded for extended periods.

It has issued a Level 3 alert - advising against all non-essential travel to Bahrain, Jordan, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates.

It advised people to consult with their travel insurance providers to understand the policy's conditions, including if government travel advisories or war exceptions could potentially void their coverage.

The European Union Aviation Safety Agency has issued advice to air operators to avoid Gulf airspace until at least July 29, and said people should check with their travel providers to confirm if flights were affected.

New Zealanders in locations where travel alerts have been issued should monitor media closely for reporting of potential targets in the region and warnings issued by local authorities.

"For those travelling, we strongly advise New Zealanders to avoid the Middle East and consider other travel routes. If you need to transit these locations, stay as short a time as possible and avoid unnecessary activities. Airspace may close at short notice. Flights can change or stop suddenly. Borders can close," the advisory said.

"US strikes had been reported in many locations across Iran including in Buschehr, Bandar Abbas, Chabahar, Konarak, Kurdistan, Sirik, Tabriz and Hamadan," it said.

Iran had targeted US military and other interests across the region and attacked or warned of attacks on civilian infrastructure including airports and water desalination facilities, the advisory said.

- Additional reporting by Reuters